Saturday 10th December – Starting the Halley modules separation


This morning got the final legs connections checked with no issues. In the afternoon the team including technical engineering staff and steelworkers went through the process of lifting each leg to break the contact with the ice and installing the polythene sheets and drilling fluid to improve the break out friction and reduce the amount of work done to separate the H2 module from H1.

Once the legs were on slip membranes and the lifting frames out of the way, the steelworkers could install the towing frame members that maintain the leg spacing during the relocation.

We got the towing frame members between the legs in place but without the A-frame or shackles. We then installed a scaled load cell and winched against the weight and friction from a D5 and D6 dozer to do a controlled separation of H2 from H1 checking all the time that the remaining services remain working within safe limits. The load was increased until almost imperceptibly the module started to move a few millimetres, and then maintaining the load was enough to open up the gap to give confidence the module was free.  We finished the day’s work with installation of the A frame, shackles and data load cell ready for the pull on Tuesday.

The A-frame is quite hard to align with the dozer in reverse and needs a nudge to get the final position set – a bit less predictable than a trailer due to ice slip and bent skis etc.  The vehicle manager also asked about the wind speed impact on the pull and we discussed the impact that 2‐3 Tons head on or laterally would have during the towing.